FX.52 Student Program: school address at the door, and applicants see what happened to our email

Owner 2026-11-05: a verified address alone does not show someone is a student, and an applicant could not tell that our email never reached them. Personal mail providers (Gmail and the like) are now refused at the form, for students and teachers. Any other host passes, because real schools often have no .edu in the address (cvut.cz, ualg.pt). After applying, the person lands on /education-status, which shows whether our email is on its way, was delivered, was refused or found no mailbox; applying again with the same address brings them back there. Only a refusal by their school's server (like the 550 5.7.1 we saw from itcgalilei.edu.it and aglousa.com) unlocks using another address; a mailbox that does not exist does not, or a made-up address would open the door. Staff see the refused address on the row. Quarantined mail reports as delivered: those people are told to write to us from the school address, and staff use "Issue without the click". Migration 123. Tests in bin/test-student-program.php (140 pass).

Not done / untested: no real outside applicant has used the page yet, and no real refusal has been seen through it (the states were set by hand on a fixture, against the live site). The personal-provider list cannot be complete and does not cover throwaway mail services. A person who knows a school that refuses mail could still name it to reach the other-address form. Nicolas and the aglousa.com applicant can only find this by coming back: we have no way to reach them.